Continuous-motion clock



H. E. WARREN CONTINUOUS MOTION CLOCK Filed May 1924 2 Sheets-Sheet l lmentor Henry E. \X/nrr'en, y J? His Attorney.

Jan, 6, 1925.

H. E. WARREN CONTINUOUS MOTION CLOCK 2 Sheets-Sheet 2 Filed May 1924 Fig. 4.

lm/ehtor' Henry Ewanen, y

His Attorney.

Patented Jan. 6, 1925.

UNITED STATES 1,522,217 PATENT OFFICE.

HENRY E. WARREN, OF ASHLAND, MASSACHUSETTS, ASSIGNOR TO TAIRIRJEIN CLOCK COMPANY, OF ASHLAND, MASSACHUSETTS, A CORPORATION OF MAINE.

CONTINUOUS-MOTION CLOCK.

Application filed May 9, 19%. Serial No. 712,120.

To all whom it may concern:

Be it known that I, HENRY E. WARREN, a citizen of the United States, residing at Ashland, in the county of Midd'lesex, State of Massachusetts, have invented certain new and useful Improvements in Continuous- Motion Clocks, of which the following is a specification.

My invention relates to a continuous motion, clock movement.

The ordinary clockmovement is provided with a form of escapement which alternately starts and stops the movement at very frequent intervals in such a way that the average feed of the movement is such as to drive the hands of the clock at the required average speed. As a consequence, the clock hands jump ahead as will be apparent by observing the second hand of a watch. The spring type of escapement is very delicate and expensive and is probably the weakest point in the clock movement of which it is a part. The ordinary spring or balance wheel escapement offers appreciable resistance to starting and in some cases must be given an impulse to set it in oscillation. here the clock is of the pendulum type, it must be started byhand even though the spring or the weight is fully wound up.

It is the object of myinvention to provide a rugged, inexpensive form of escapement which permits a gliding movement of the clock hand or other parts driven by the movement rather than a jumping movement and an escapement which is comparatively insensitive to changes in the clock level and which offers no resistance to starting other than the friction of the parts. Because of the gliding movement which my improved form of escapement provides, the clock equipped therewith is especially adapted for timing exceedingly small intervals where an ordinary clock would give erroneous results. My improved clock movement may be provided with a simple lock or brake and the movement started by simply releasing the lock or brake.

In carrying my invention into effect, I provide a simple, rugged escapement or governor which operates on the principle of balancing centrifugal force against gravity. The features of my invention which I believe'to be novel and patentable will be pointed out in the claims appended hereto. For a better understanding of my invention, reference is made in the following description to the .accompanying drawings, Fig. 1 of which is a side view of a clock movement equipped with my improved escapemcnt; Fig. 2 shows a top view of the escapcment of Fig. 1; Fig. 3 shows a perspective view of a regulating device for the escapeinent of Fig. 1; Fig. 4 shows a side view of a clock movement in general similar to Fig. 1, but provided with a friction drive instead of a gear drive for the escapement; Fig. 5 is a top view of the escapement drive of Fig. 4; Fig. 6 shows a modification Where a combined friction and gear drive for the escapement is used; Fig. 7 is a top view of the escapement drive of Fig. 6; Fig. 8 shows a clock drive having in addition to my improved escapement, a remontoir movement, or second es'capement, between the clock spring and the main escapement for equalizing the force of the driving spring; and Fig 9 shows a top view of the escapements of Fig. 8.

Referring to Fig. 1, 10 represents a gear driven by a clock spring 9 in the usual manner. Motion is transmitted through the gear train 11. 12, 13, and 14 tothe gear 15 and this, in turn, engages with the pinion 16 shown more clearly in Fig. 2, the pinion 16 being mounted near the center of shaft 17. The bearing for the shaft 17 is at the bottom of slots 18 in the clock plates 19 and the clock plates 19 serve as hearing supports for the other rotating parts of the clock. Near the outer end of shaft 17 are mounted centrifugal weights 20' and 21 conveniently made in theform of These sectors are secured in fixed relation on the shaft 17 at an angle of 180 to each other. Consequently they are in equilibrium. so far as gravity is concerned and the do not have a tendency to vibrate. the sha 17 due to centrifugal force when it isrotating slowly.

With the device as shown, when the spring 9 is wound up, shaft 17 willbegin to rotate without a primary impulse such as is required with a pendulum or balance wheel escapement. The speed of rotation of shaft 17 will increase until a point is reached where the centrifugal force of the sectors 20 and 21 becomes greater than the weight of these sectors. After this critical speed has bee e e thesectors as they revolve, will alternately lift the ends of the shaft 17 to which they are attached in the slots 18 provided in the clock plates 19. There will thus result a forced vibration of the whole system consisting of the shaft 17, pinion 16 and sectors 20 and 21 with the minimum amount of vibration of the system at the center of shaft 17 where the pinion 16 is mounted. This forced vibra tion of the system can only be maintained by the absorption of energy received through'the train of gears from the spring 9 and when the amount of energy so absorbed is equal to the output, no further velocity of the rotation of shaft 1.7 can occur.

Whenv the parts are properly 'proportioned, I have found that itis perfectly feasible to absorb all the excess energy of a clock spring in maintaining a very slight amount of vibration of the shaft 17 and that under these conditions, an exceedingly accurate and reliable speed governor is secured. This governor corresponds to the ordinary escapement of a clock with this difference; with my improved form of escapement the motion of the clock movement is continuous instead of an alternate starting and stopping as is the case with the usual form of escapement. Clock hands 8 may therefore be attached to or driven by a proper member ofthe gear train as illustrated at 8, or the device may be usedfor any other purpose for which a clock movement is essential.

Fig. 4 shows a further development of the scheme in which the friction of the fast running shaft 17 is reduced by causing it to rest upon the edges of revolving disks 22 and 23 mounted upon the shaft 24. In this case there is a friction drive to the shaft 17 at the enlarged portions 25 and 26 of shaft 17 in place of the gear drives 15 and 16 in Figs. 1 and 2. The friction of the shaft 17 at the bottom of the slots 18 is practically eliminated. I have found this to be a feasible construction. but there is a slight tendency of slipping between sectors 22 and 23 and the parts 25 and 26 which they drive and therefore I have shown a still further improvement in Fig. 6 where there is a combination of both methods used in Figs. 1 and 4. namely, gears 15, 16 and the friction disks 22. 23, making contact with the shaft 17 at points 25 and 26. With the construction shown in Figs. 6 and 7 the drive is normally by friction and the 'ears which are comparatively loose serve only as a safeguard a ainst ossible sli in due to the vibratiori of the shaft 17. Pp g The device so far described is capable of maintaining the speed of the clock movement substantially correct, but it is of course obvious that when the spring of the gear train is tightly wound, the amount of energy delivered to the vibratingshaft 17 will be greater than it is when the clock spring is nearly run down and therefore in the former case this shaft will vibrate further, which means that it will run slightly faster than when the spring 9 is nearly run down. If the spring of gear 10 is replaced with a constant driving force such as a weight, this error in'speed will not occur, but in Figs. 9 and 8, I have shown another method of serving a uniform driving force from a clock spring to the vibrating shaft 17 irrespective of the tension of the clock spring. This is accomplished by a very simple form of remontoir movement in which one member of the gear train consists of a heavily weighted shaft 27 of which one end is loosely pivoted at 28 in one of the clock plates and the other end is free to move up and down in the slot 29 of the other clock plate. The outer end of this shaft 27 carries a ratchet wheel 30 which serves also as a Weight. A stop 31 is provided on the clock plate above the ratchet wheel to check the rotation of this ratchet wheel 30 when the shaft 27 rises in the slot 29. Pinions 32 and 33 shown more clearly in Fig. 9 carry rotation motion from the gear 13 to the gear 14. With the arrangement as shown, if the linear velocity at the pitch line of gear 33 is greater than the linear velocity at the pitch line of gear 14, the former will roll upward and lift the shaft 27 in the $101729, thus causing the ratchet 30 to lock against the stop 31. When this hap )ens, the'weight of the gears upon the shal t 27, together with the weight of the shaft itself will alone be available to continue the rotation of 14 and this weight will measure the maximum force which can be transmitted at a time when the spring of the clock is fully wound. Consequently, this force will be uniform and the rate of the controlling shaft 17 of the second escapement will be constant. As soon as shaft 27 has dropped a sufiicient distance to unlock a tooth of the ratchet wheel 30, shaft 23 will again rise. and the next tooth will engage the stop 31 and this action will continue until the spring has run down.

For the purpose of adjusting the rate of the clock movement, radius screws 34 and 35, Fig. 6 and Fig. 8 may be provided and adjusted toward or away from the shaft, or

the tendency of gravity to pull the shaft 17 with its load downward may be partially balanced by an adjustable magnet 36 shown in Figs. 1 and 3, tending to pull the same parts upward.

I prefer to make the sectors 20 and 21 from some material such as invar having a very low temperature coefiicient of expansion so that the rate of the clock movement will not be appreciably affected by temperature changes. It will be noted-that in all cases, the direction of rotation of the gear is such as to have a lifting tendency on shaft 17. I

This centrifugal speed governor form of escapement is rugged in construction and economical to manufacture and should continue to run a long period of time without attention or appreciable wear. Due to the fact that the device is not appreciably affected, by changes in level, it may advantageously be used on shipboard where a pendulum clock would be out of the question.

In accordance with the provisions of the patent statutes, I have described the principle of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof; but I desire to have it understood that the apparatus shown and described is only illustrative and that the invention may be car ried out by other arrangements.

Vhat I claim as new and desire to secure by Letters Patent of the United States, is,

1. All escapement mechanism comprising a supporting member, a substantially horizontal shaft rotatably mounted by being supported at its ends in substantially vertical slots in said supporting member, a pair of weights secured adjacent the opposite end of said shaft and on opposite sides thereof, and means for rotating said shaft at a sufficient speed to cause the shaft to vibrate in said slots due to centrifugal force.

2. A clock movement comprising a driving. means, a train of gears driven thereby and an escapement as claimed in claim 1, driven from said gear train.

3. An escapement mechanism comprising a stationary framework, a substantially horizontal shaft rotatably supported at its ends in substantially Vertical slots in said framework, a pair of similar weights attached to opposite sides of said shaft, one adjacent each end, and means for driving ""said -shaftmidwayjoetpnszen said weights.

4. An escapement mechanism comprising a framework, a substantlally horizontal shaft rotatably supported at its ends iiisubstantially vertical slots in said framework, a

pair of similar weights secured on opposite sides of said shaft, one adjacent each end, means for driving said shaft at a speed sufficient to cause the same to vibrate in said slots due to centrifugal force, and means for adjusting the vibrating speed of said shaft.

An est-apement' mechanism comprising a fran'iework, a substantially horizontal shaft rotatably supported at its ends in said framework, a pair of similar weights secured to opposite sides of said shaft, one adjacent each end, said weights being made of a material having a negligible temperature coefiieient of expansion, and means for driving said shaft at a speed suflicient to cause said shaft to vibrate up and down in said slots due to the action of centrifugal force upon said weights.

6. A clock movement comprising a driving spring, a speed multiplying gear train driven thereby, a centrifugal governor escapement driven from the high speed ends of said gear train and a remontoir movement included in said gear train.

7. A clock movement comprising a gear train, a driving spring, an escapement and a remontoir movement therefor, said remontoir movement comprising a weighted shaft rotatably mounted in a substantially horizontal position with at least one end free to move up and down vertically, a ratchet wheel on a vertically movable portion of said shaft, a stop for said ratchet wheel positioned to engage and stop the rotation of said wheel, when the shaft is raised, and gears on said shaft included in said gear train, said remontoir movement being included in said gear train in such a way that the shaft is raised by the driving force of said spring and when raised constitutes a driving forcefor said escapement,

8. A clock movement comprising driving means. a speed multiplying gear train driven by said driving means,- and a centrifugal governor forming an escapement for said clock movement driven from the high speed end of said gear train.

In witness whereof, I have hereunto set my hand this 6th day of May, 1924.

' HENRY E. WARREN. 

